The present disclosure pertains to a process for preparing self-dispersing pigments, in particular to self-dispersing inorganic particles, and in particular to titanium dioxide pigments, and their use in décor paper and paper laminates made from such paper.
Paper laminates are in general well-known in the art, being suitable for a variety of uses including table and desk tops, countertops, wall panels, floor surfacing and the like. Paper laminates have such a wide variety of uses because they can be made to be extremely durable, and can be also made to resemble (both in appearance and texture) a wide variety of construction materials, including wood, stone, marble and tile, and they can be decorated to carry images and colors.
Typically, the paper laminates are made from décor paper by impregnating the paper with resins of various kinds, assembling several layers of one or more types of laminate papers, and consolidating the assembly into a unitary core structure while converting the resin to a cured state. The type of resin and laminate paper used, and composition of the final assembly, are generally dictated by the end use of the laminate.
Decorative paper laminates can be made by utilizing a decorated paper layer as the visible paper layer in the unitary core structure. The remainder of the core structure typically comprises various support paper layers, and may include one or more highly-opaque intermediate layers between the decorative and support layers so that the appearance of the support layers does not adversely impact the appearance of decorative layer.
Paper laminates may be produced by both low- and high-pressure lamination processes.
Décor papers typically comprise fillers such as titanium dioxide to increase brightness and opacity to the paper. Typically, these fillers are incorporated into the fibrous paper web by wet end addition.
Often encountered in the décor paper making process are conditions where the pigment interacts with furnish components like wet strength resin and/or paper fibers in such a way that is detrimental to formation of the paper matrix. This negative interaction can be manifested as a loss in paper tensile strength (wet or dry), or a mottled appearance in the finished sheet, or poor opacity. Thus a need exists for a self-dispersing pigment that exhibits improved compatibility with components in the paper making furnish.